Methods of making paper tissue, towel, and the like are well known, including various features such as Yankee drying, throughdrying, fabric creping, dry creping, wet creping and so forth. Conventional wet pressing/dry creping processes have certain advantages over conventional through-air drying processes including: (1) lower energy costs associated with the mechanical removal of water rather than transpiration drying with hot air; and (2) higher production speeds which are more readily achieved with processes which utilize wet pressing to form a web. On the other hand, through-air drying processing has been widely adopted for new capital investment, particularly for the production of soft, bulky, premium quality towel products.
Fabric creping has been employed in connection with papermaking processes which include mechanical or compactive dewatering of the paper web as a means to influence product properties. See U.S. Pat. Nos. 4,689,119 and 4,551,199 to Weldon; 4,849,054 and 4,834,838 to Klowak; and 6,287,426 to Edwards et al. Operation of fabric creping processes has been hampered by the difficulty of effectively transferring a web of high or intermediate consistency to a dryer. Note also U.S. Pat. No. 6,350,349 to Hermans et al. which discloses wet transfer of a web from a rotating transfer surface to a fabric. Further United States Patents relating to fabric creping more generally include the following: U.S. Pat. Nos. 4,834,838; 4,482,429; 4,445,638 as well as U.S. Pat. No. 4,440,597 to Wells et al. Typically, the fabric creped webs are dried, then dry-creped.
Throughdried, creped products are disclosed in the following patents: U.S. Pat. No. 3,994,771 to Morgan, Jr. et al.; U.S. Pat. No. 4,102,737 to Morton; and U.S. Pat. No. 4,529,480 to Trokhan. The processes described in these patents comprise, very generally, forming a web on a foraminous support, thermally pre-drying the web, applying the web to a Yankee dryer with a nip defined, in part, by an impression fabric, and creping the product from the Yankee dryer. A relatively permeable web is typically required, making it difficult to employ recycle furnish at levels which may be desired. Transfer to the Yankee typically takes place at web consistencies of from about 60% to about 70%. See also, U.S. Pat. No. 6,187,137 to Druecke et al. which includes disclosure of peeling a web from a Yankee dryer.
As noted in the above, throughdried products tend to exhibit enhanced bulk and softness; however, thermal dewatering with hot air tends to be energy intensive. Wet-press/dry crepe operations wherein the webs are mechanically dewatered are preferable from an energy perspective and are more readily applied to furnishes containing recycle fiber which tends to form webs with less uniform permeability than virgin fiber. Moreover, line speeds tend to be higher with wet-press operations.
Automatic towel dispensers introduced in recent years are preferred in many respects by consumers, business establishments and institutions since better hygiene and superior dispensing control is provided. Such dispensers are seen in the following patents: Sheet Material Dispenser with Perforation Sensor and Method, U.S. Pat. No. 6,766,977 to Denen et al. which discloses a paper dispenser releasing individual sheets of paper in response to movement (once the dispenser detects movement, it releases paper and activates a perforation sensor to stop advancement of the roll of paper after a set number of rotations); Waste Minimizing Paper Dispenser, U.S. Pat. No. 6,793,170 to Denen et al. describes a dispenser for dispensing paper from two rolls, the dispenser releases paper from the first roll until a sensor detects its reduction to a predetermined size whereupon the dispenser releases paper from both rolls until one of the rolls is depleted; Minimizing Paper Waste Carousel-Style Dispenser, Sensor, Method and System with Proximity Sensor, U.S. Pat. No. 6,592,067 to Denen et al. which discloses and claims an apparatus dispensing paper upon detection of a hand next to it which has a movement sensor containing an electrical circuit measuring change of capacitance as a result of proximity of a hand; see also Proximity Detection Circuit and Method of Detecting Small Capacitance Changes, U.S. Pat. No. 6,838,887 where there is described a second miniaturized circuit which is added for detecting proximity of a hand; as well as Static Build Up in Electronic Dispensing System U.S. Pat. No. 6,871,815 to Moody et al. which provides for a system for dissipating static electrical build-up to local ground via a metal contact between the high conductivity pathway and, for example, the wall against which the dispenser is mounted. Further features are seen in U.S. Pat. Nos. 6,412,678 and 6,321,963 to Gracyalny et al.
It has been found that unacceptable dispensing failure rates are experienced when using typical wet-pressed/dry creped towel in these automatic dispensers, so much so that relatively expensive throughdried products with relatively high bending length are ordinarily required with these very popular automatic dispensers.
It has been found in accordance with the present invention that wet pressed/fabric creped towel with a unique combination of properties suitable for automatic dispensers can be produced without dry creping provided the wet-press manufacturing process is suitably controlled. The present invention thus provides economical feedstock for automatic dispensers which readily incorporates recycle fiber and which may be produced at higher line speeds and with lower energy costs than throughdried products.